A magnetizing apparatus provided with a magnetizing yoke arranged with plural magnetizing coils in a radial pattern or in a circumferential manner has been used for magnetizing a magnetic encoder provided with the south pole and the north pole in a circumferential manner. Positioning hole is provided at the center of the magnetizing yoke as the center of the yoke, the magnetic encoder base plate to be magnetized is placed thereon or is faced each other to be fixed with a presser jig, then the magnetizing current is externally supplied to a wire of a magnetizing coil to achieve multi-pole magnetizing on the magnetic encoder on which the S poles and N poles are alternately arranged (for example, JP-A-10-115628).